Loading frames, in addition to shaping and stiffening the fuselage of an aircraft, are structural elements designed to withstand and transfer loads from other structural elements in the aircraft, such as the wings and stabilisers.
Traditionally, loading frames have been made from metal material and have had various cross sections, with the most common being C-, I- and J-shaped, and which, by means of machining processes, form a framework of stiffeners which stabilise the webs in the frame.
In today's aeronautical industry, the strength-weight ratio is of supreme importance which means that there is a demand for frames made from, or optimised using, composite materials, mainly carbon fibre, rather than metal frames.
In the case of loading frames it is difficult to compete with machined metal frames since, due to the large amounts of different types of stress they have to withstand, alternative frames in composite materials usually pose diverse manufacturing problems due to their rather complex design. In any event, several solutions in this area are already known, such as those described in patent applications WO 2008/092970, US 2009/0026315 and WO 2009/030731.
One of the aforementioned problems relates to attempting to produce a frame design with stabilised webs which would enable weight to be optimised. Although several solutions are already known for forming frames, none are available for loading frames in spite of the current demand for such frames in the aeronautical industry.
The invention is aimed at meeting this demand.